[linux.git] / fs / hfsplus / brec.c

/*
 *  linux/fs/hfsplus/brec.c
 *
 * Copyright (C) 2001
 * Brad Boyer ([email protected])
 * (C) 2003 Ardis Technologies <[email protected]>
 *
 * Handle individual btree records
 */

#include "hfsplus_fs.h"
#include "hfsplus_raw.h"

static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
static int hfs_brec_update_parent(struct hfs_find_data *fd);
static int hfs_btree_inc_height(struct hfs_btree *);

/* Get the length and offset of the given record in the given node */
u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off)
{
	__be16 retval[2];
	u16 dataoff;

	dataoff = node->tree->node_size - (rec + 2) * 2;
	hfs_bnode_read(node, retval, dataoff, 4);
	*off = be16_to_cpu(retval[1]);
	return be16_to_cpu(retval[0]) - *off;
}

/* Get the length of the key from a keyed record */
u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
{
	u16 retval, recoff;

	if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
		return 0;

	if ((node->type == HFS_NODE_INDEX) &&
	   !(node->tree->attributes & HFS_TREE_VARIDXKEYS) &&
	   (node->tree->cnid != HFSPLUS_ATTR_CNID)) {
		retval = node->tree->max_key_len + 2;
	} else {
		recoff = hfs_bnode_read_u16(node,
			node->tree->node_size - (rec + 1) * 2);
		if (!recoff)
			return 0;
		if (recoff > node->tree->node_size - 2) {
			pr_err("recoff %d too large\n", recoff);
			return 0;
		}

		retval = hfs_bnode_read_u16(node, recoff) + 2;
		if (retval > node->tree->max_key_len + 2) {
			pr_err("keylen %d too large\n",
				retval);
			retval = 0;
		}
	}
	return retval;
}

int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
{
	struct hfs_btree *tree;
	struct hfs_bnode *node, *new_node;
	int size, key_len, rec;
	int data_off, end_off;
	int idx_rec_off, data_rec_off, end_rec_off;
	__be32 cnid;

	tree = fd->tree;
	if (!fd->bnode) {
		if (!tree->root)
			hfs_btree_inc_height(tree);
		fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
		if (IS_ERR(fd->bnode))
			return PTR_ERR(fd->bnode);
		fd->record = -1;
	}
	new_node = NULL;
	key_len = be16_to_cpu(fd->search_key->key_len) + 2;
again:
	/* new record idx and complete record size */
	rec = fd->record + 1;
	size = key_len + entry_len;

	node = fd->bnode;
	hfs_bnode_dump(node);
	/* get last offset */
	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
	end_off = hfs_bnode_read_u16(node, end_rec_off);
	end_rec_off -= 2;
	hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
		rec, size, end_off, end_rec_off);
	if (size > end_rec_off - end_off) {
		if (new_node)
			panic("not enough room!\n");
		new_node = hfs_bnode_split(fd);
		if (IS_ERR(new_node))
			return PTR_ERR(new_node);
		goto again;
	}
	if (node->type == HFS_NODE_LEAF) {
		tree->leaf_count++;
		mark_inode_dirty(tree->inode);
	}
	node->num_recs++;
	/* write new last offset */
	hfs_bnode_write_u16(node,
		offsetof(struct hfs_bnode_desc, num_recs),
		node->num_recs);
	hfs_bnode_write_u16(node, end_rec_off, end_off + size);
	data_off = end_off;
	data_rec_off = end_rec_off + 2;
	idx_rec_off = tree->node_size - (rec + 1) * 2;
	if (idx_rec_off == data_rec_off)
		goto skip;
	/* move all following entries */
	do {
		data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
		hfs_bnode_write_u16(node, data_rec_off, data_off + size);
		data_rec_off += 2;
	} while (data_rec_off < idx_rec_off);

	/* move data away */
	hfs_bnode_move(node, data_off + size, data_off,
		       end_off - data_off);

skip:
	hfs_bnode_write(node, fd->search_key, data_off, key_len);
	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
	hfs_bnode_dump(node);

	/*
	 * update parent key if we inserted a key
	 * at the start of the node and it is not the new node
	 */
	if (!rec && new_node != node) {
		hfs_bnode_read_key(node, fd->search_key, data_off + size);
		hfs_brec_update_parent(fd);
	}

	if (new_node) {
		hfs_bnode_put(fd->bnode);
		if (!new_node->parent) {
			hfs_btree_inc_height(tree);
			new_node->parent = tree->root;
		}
		fd->bnode = hfs_bnode_find(tree, new_node->parent);

		/* create index data entry */
		cnid = cpu_to_be32(new_node->this);
		entry = &cnid;
		entry_len = sizeof(cnid);

		/* get index key */
		hfs_bnode_read_key(new_node, fd->search_key, 14);
		__hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key);

		hfs_bnode_put(new_node);
		new_node = NULL;

		if ((tree->attributes & HFS_TREE_VARIDXKEYS) ||
				(tree->cnid == HFSPLUS_ATTR_CNID))
			key_len = be16_to_cpu(fd->search_key->key_len) + 2;
		else {
			fd->search_key->key_len =
				cpu_to_be16(tree->max_key_len);
			key_len = tree->max_key_len + 2;
		}
		goto again;
	}

	return 0;
}

int hfs_brec_remove(struct hfs_find_data *fd)
{
	struct hfs_btree *tree;
	struct hfs_bnode *node, *parent;
	int end_off, rec_off, data_off, size;

	tree = fd->tree;
	node = fd->bnode;
again:
	rec_off = tree->node_size - (fd->record + 2) * 2;
	end_off = tree->node_size - (node->num_recs + 1) * 2;

	if (node->type == HFS_NODE_LEAF) {
		tree->leaf_count--;
		mark_inode_dirty(tree->inode);
	}
	hfs_bnode_dump(node);
	hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n",
		fd->record, fd->keylength + fd->entrylength);
	if (!--node->num_recs) {
		hfs_bnode_unlink(node);
		if (!node->parent)
			return 0;
		parent = hfs_bnode_find(tree, node->parent);
		if (IS_ERR(parent))
			return PTR_ERR(parent);
		hfs_bnode_put(node);
		node = fd->bnode = parent;

		__hfs_brec_find(node, fd, hfs_find_rec_by_key);
		goto again;
	}
	hfs_bnode_write_u16(node,
		offsetof(struct hfs_bnode_desc, num_recs),
		node->num_recs);

	if (rec_off == end_off)
		goto skip;
	size = fd->keylength + fd->entrylength;

	do {
		data_off = hfs_bnode_read_u16(node, rec_off);
		hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
		rec_off -= 2;
	} while (rec_off >= end_off);

	/* fill hole */
	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
		       data_off - fd->keyoffset - size);
skip:
	hfs_bnode_dump(node);
	if (!fd->record)
		hfs_brec_update_parent(fd);
	return 0;
}

static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
{
	struct hfs_btree *tree;
	struct hfs_bnode *node, *new_node, *next_node;
	struct hfs_bnode_desc node_desc;
	int num_recs, new_rec_off, new_off, old_rec_off;
	int data_start, data_end, size;

	tree = fd->tree;
	node = fd->bnode;
	new_node = hfs_bmap_alloc(tree);
	if (IS_ERR(new_node))
		return new_node;
	hfs_bnode_get(node);
	hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n",
		node->this, new_node->this, node->next);
	new_node->next = node->next;
	new_node->prev = node->this;
	new_node->parent = node->parent;
	new_node->type = node->type;
	new_node->height = node->height;

	if (node->next)
		next_node = hfs_bnode_find(tree, node->next);
	else
		next_node = NULL;

	if (IS_ERR(next_node)) {
		hfs_bnode_put(node);
		hfs_bnode_put(new_node);
		return next_node;
	}

	size = tree->node_size / 2 - node->num_recs * 2 - 14;
	old_rec_off = tree->node_size - 4;
	num_recs = 1;
	for (;;) {
		data_start = hfs_bnode_read_u16(node, old_rec_off);
		if (data_start > size)
			break;
		old_rec_off -= 2;
		if (++num_recs < node->num_recs)
			continue;
		/* panic? */
		hfs_bnode_put(node);
		hfs_bnode_put(new_node);
		if (next_node)
			hfs_bnode_put(next_node);
		return ERR_PTR(-ENOSPC);
	}

	if (fd->record + 1 < num_recs) {
		/* new record is in the lower half,
		 * so leave some more space there
		 */
		old_rec_off += 2;
		num_recs--;
		data_start = hfs_bnode_read_u16(node, old_rec_off);
	} else {
		hfs_bnode_put(node);
		hfs_bnode_get(new_node);
		fd->bnode = new_node;
		fd->record -= num_recs;
		fd->keyoffset -= data_start - 14;
		fd->entryoffset -= data_start - 14;
	}
	new_node->num_recs = node->num_recs - num_recs;
	node->num_recs = num_recs;

	new_rec_off = tree->node_size - 2;
	new_off = 14;
	size = data_start - new_off;
	num_recs = new_node->num_recs;
	data_end = data_start;
	while (num_recs) {
		hfs_bnode_write_u16(new_node, new_rec_off, new_off);
		old_rec_off -= 2;
		new_rec_off -= 2;
		data_end = hfs_bnode_read_u16(node, old_rec_off);
		new_off = data_end - size;
		num_recs--;
	}
	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);

	/* update new bnode header */
	node_desc.next = cpu_to_be32(new_node->next);
	node_desc.prev = cpu_to_be32(new_node->prev);
	node_desc.type = new_node->type;
	node_desc.height = new_node->height;
	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	node_desc.reserved = 0;
	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));

	/* update previous bnode header */
	node->next = new_node->this;
	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
	node_desc.next = cpu_to_be32(node->next);
	node_desc.num_recs = cpu_to_be16(node->num_recs);
	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));

	/* update next bnode header */
	if (next_node) {
		next_node->prev = new_node->this;
		hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
		node_desc.prev = cpu_to_be32(next_node->prev);
		hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
		hfs_bnode_put(next_node);
	} else if (node->this == tree->leaf_tail) {
		/* if there is no next node, this might be the new tail */
		tree->leaf_tail = new_node->this;
		mark_inode_dirty(tree->inode);
	}

	hfs_bnode_dump(node);
	hfs_bnode_dump(new_node);
	hfs_bnode_put(node);

	return new_node;
}

static int hfs_brec_update_parent(struct hfs_find_data *fd)
{
	struct hfs_btree *tree;
	struct hfs_bnode *node, *new_node, *parent;
	int newkeylen, diff;
	int rec, rec_off, end_rec_off;
	int start_off, end_off;

	tree = fd->tree;
	node = fd->bnode;
	new_node = NULL;
	if (!node->parent)
		return 0;

again:
	parent = hfs_bnode_find(tree, node->parent);
	if (IS_ERR(parent))
		return PTR_ERR(parent);
	__hfs_brec_find(parent, fd, hfs_find_rec_by_key);
	if (fd->record < 0)
		return -ENOENT;
	hfs_bnode_dump(parent);
	rec = fd->record;

	/* size difference between old and new key */
	if ((tree->attributes & HFS_TREE_VARIDXKEYS) ||
				(tree->cnid == HFSPLUS_ATTR_CNID))
		newkeylen = hfs_bnode_read_u16(node, 14) + 2;
	else
		fd->keylength = newkeylen = tree->max_key_len + 2;
	hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n",
		rec, fd->keylength, newkeylen);

	rec_off = tree->node_size - (rec + 2) * 2;
	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
	diff = newkeylen - fd->keylength;
	if (!diff)
		goto skip;
	if (diff > 0) {
		end_off = hfs_bnode_read_u16(parent, end_rec_off);
		if (end_rec_off - end_off < diff) {

			hfs_dbg(BNODE_MOD, "splitting index node\n");
			fd->bnode = parent;
			new_node = hfs_bnode_split(fd);
			if (IS_ERR(new_node))
				return PTR_ERR(new_node);
			parent = fd->bnode;
			rec = fd->record;
			rec_off = tree->node_size - (rec + 2) * 2;
			end_rec_off = tree->node_size -
				(parent->num_recs + 1) * 2;
		}
	}

	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
	start_off -= 4;	/* move previous cnid too */

	while (rec_off > end_rec_off) {
		rec_off -= 2;
		end_off = hfs_bnode_read_u16(parent, rec_off);
		hfs_bnode_write_u16(parent, rec_off, end_off + diff);
	}
	hfs_bnode_move(parent, start_off + diff, start_off,
		       end_off - start_off);
skip:
	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
	hfs_bnode_dump(parent);

	hfs_bnode_put(node);
	node = parent;

	if (new_node) {
		__be32 cnid;

		fd->bnode = hfs_bnode_find(tree, new_node->parent);
		/* create index key and entry */
		hfs_bnode_read_key(new_node, fd->search_key, 14);
		cnid = cpu_to_be32(new_node->this);

		__hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key);
		hfs_brec_insert(fd, &cnid, sizeof(cnid));
		hfs_bnode_put(fd->bnode);
		hfs_bnode_put(new_node);

		if (!rec) {
			if (new_node == node)
				goto out;
			/* restore search_key */
			hfs_bnode_read_key(node, fd->search_key, 14);
		}
	}

	if (!rec && node->parent)
		goto again;
out:
	fd->bnode = node;
	return 0;
}

static int hfs_btree_inc_height(struct hfs_btree *tree)
{
	struct hfs_bnode *node, *new_node;
	struct hfs_bnode_desc node_desc;
	int key_size, rec;
	__be32 cnid;

	node = NULL;
	if (tree->root) {
		node = hfs_bnode_find(tree, tree->root);
		if (IS_ERR(node))
			return PTR_ERR(node);
	}
	new_node = hfs_bmap_alloc(tree);
	if (IS_ERR(new_node)) {
		hfs_bnode_put(node);
		return PTR_ERR(new_node);
	}

	tree->root = new_node->this;
	if (!tree->depth) {
		tree->leaf_head = tree->leaf_tail = new_node->this;
		new_node->type = HFS_NODE_LEAF;
		new_node->num_recs = 0;
	} else {
		new_node->type = HFS_NODE_INDEX;
		new_node->num_recs = 1;
	}
	new_node->parent = 0;
	new_node->next = 0;
	new_node->prev = 0;
	new_node->height = ++tree->depth;

	node_desc.next = cpu_to_be32(new_node->next);
	node_desc.prev = cpu_to_be32(new_node->prev);
	node_desc.type = new_node->type;
	node_desc.height = new_node->height;
	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	node_desc.reserved = 0;
	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));

	rec = tree->node_size - 2;
	hfs_bnode_write_u16(new_node, rec, 14);

	if (node) {
		/* insert old root idx into new root */
		node->parent = tree->root;
		if (node->type == HFS_NODE_LEAF ||
				tree->attributes & HFS_TREE_VARIDXKEYS ||
				tree->cnid == HFSPLUS_ATTR_CNID)
			key_size = hfs_bnode_read_u16(node, 14) + 2;
		else
			key_size = tree->max_key_len + 2;
		hfs_bnode_copy(new_node, 14, node, 14, key_size);

		if (!(tree->attributes & HFS_TREE_VARIDXKEYS) &&
				(tree->cnid != HFSPLUS_ATTR_CNID)) {
			key_size = tree->max_key_len + 2;
			hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
		}
		cnid = cpu_to_be32(node->this);
		hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);

		rec -= 2;
		hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);

		hfs_bnode_put(node);
	}
	hfs_bnode_put(new_node);
	mark_inode_dirty(tree->inode);

	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hfsplus/brec.c
	3	*
	4	* Copyright (C) 2001
	5	* Brad Boyer ([email protected])
	6	* (C) 2003 Ardis Technologies <[email protected]>
	7	*
	8	* Handle individual btree records
	9	*/
	10
	11	#include "hfsplus_fs.h"
	12	#include "hfsplus_raw.h"
	13
	14	static struct hfs_bnode hfs_bnode_split(struct hfs_find_data fd);
	15	static int hfs_brec_update_parent(struct hfs_find_data *fd);
	16	static int hfs_btree_inc_height(struct hfs_btree *);
	17
	18	/* Get the length and offset of the given record in the given node */
	19	u16 hfs_brec_lenoff(struct hfs_bnode node, u16 rec, u16 off)
	20	{
	21	__be16 retval[2];
	22	u16 dataoff;
	23
	24	dataoff = node->tree->node_size - (rec + 2) * 2;
	25	hfs_bnode_read(node, retval, dataoff, 4);
	26	*off = be16_to_cpu(retval[1]);
	27	return be16_to_cpu(retval[0]) - *off;
	28	}
	29
	30	/* Get the length of the key from a keyed record */
	31	u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
	32	{
	33	u16 retval, recoff;
	34
	35	if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
	36	return 0;
	37
	38	if ((node->type == HFS_NODE_INDEX) &&
324ef39a VD	39	!(node->tree->attributes & HFS_TREE_VARIDXKEYS) &&
324ef39a VD	40	(node->tree->cnid != HFSPLUS_ATTR_CNID)) {
1da177e4 LT	41	retval = node->tree->max_key_len + 2;
1da177e4 LT	42	} else {
2753cc28 AS	43	recoff = hfs_bnode_read_u16(node,
2753cc28 AS	44	node->tree->node_size - (rec + 1) * 2);
1da177e4 LT	45	if (!recoff)
1da177e4 LT	46	return 0;
aac4e419	47	if (recoff > node->tree->node_size - 2) {
d6142673	48	pr_err("recoff %d too large\n", recoff);
aac4e419 NA	49	return 0;
aac4e419 NA	50	}
13571a69 CH	51
	52	retval = hfs_bnode_read_u16(node, recoff) + 2;
	53	if (retval > node->tree->max_key_len + 2) {
d6142673	54	pr_err("keylen %d too large\n",
13571a69 CH	55	retval);
13571a69 CH	56	retval = 0;
9250f925	57	}
1da177e4 LT	58	}
	59	return retval;
	60	}
	61
	62	int hfs_brec_insert(struct hfs_find_data fd, void entry, int entry_len)
	63	{
	64	struct hfs_btree *tree;
	65	struct hfs_bnode node, new_node;
	66	int size, key_len, rec;
	67	int data_off, end_off;
	68	int idx_rec_off, data_rec_off, end_rec_off;
	69	__be32 cnid;
	70
	71	tree = fd->tree;
	72	if (!fd->bnode) {
	73	if (!tree->root)
	74	hfs_btree_inc_height(tree);
	75	fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
	76	if (IS_ERR(fd->bnode))
	77	return PTR_ERR(fd->bnode);
	78	fd->record = -1;
	79	}
	80	new_node = NULL;
	81	key_len = be16_to_cpu(fd->search_key->key_len) + 2;
	82	again:
	83	/* new record idx and complete record size */
	84	rec = fd->record + 1;
	85	size = key_len + entry_len;
	86
	87	node = fd->bnode;
	88	hfs_bnode_dump(node);
	89	/* get last offset */
	90	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
	91	end_off = hfs_bnode_read_u16(node, end_rec_off);
	92	end_rec_off -= 2;
c2b3e1f7	93	hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
2753cc28	94	rec, size, end_off, end_rec_off);
1da177e4 LT	95	if (size > end_rec_off - end_off) {
	96	if (new_node)
	97	panic("not enough room!\n");
	98	new_node = hfs_bnode_split(fd);
	99	if (IS_ERR(new_node))
	100	return PTR_ERR(new_node);
	101	goto again;
	102	}
	103	if (node->type == HFS_NODE_LEAF) {
	104	tree->leaf_count++;
	105	mark_inode_dirty(tree->inode);
	106	}
	107	node->num_recs++;
	108	/* write new last offset */
2753cc28 AS	109	hfs_bnode_write_u16(node,
	110	offsetof(struct hfs_bnode_desc, num_recs),
	111	node->num_recs);
1da177e4 LT	112	hfs_bnode_write_u16(node, end_rec_off, end_off + size);
	113	data_off = end_off;
	114	data_rec_off = end_rec_off + 2;
	115	idx_rec_off = tree->node_size - (rec + 1) * 2;
	116	if (idx_rec_off == data_rec_off)
	117	goto skip;
	118	/* move all following entries */
	119	do {
	120	data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
	121	hfs_bnode_write_u16(node, data_rec_off, data_off + size);
	122	data_rec_off += 2;
	123	} while (data_rec_off < idx_rec_off);
	124
	125	/* move data away */
	126	hfs_bnode_move(node, data_off + size, data_off,
	127	end_off - data_off);
	128
	129	skip:
	130	hfs_bnode_write(node, fd->search_key, data_off, key_len);
	131	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
	132	hfs_bnode_dump(node);
	133
98cf21c6 SA	134	/*
	135	* update parent key if we inserted a key
	136	* at the start of the node and it is not the new node
	137	*/
	138	if (!rec && new_node != node) {
	139	hfs_bnode_read_key(node, fd->search_key, data_off + size);
	140	hfs_brec_update_parent(fd);
	141	}
1da177e4	142
98cf21c6	143	if (new_node) {
1da177e4 LT	144	hfs_bnode_put(fd->bnode);
	145	if (!new_node->parent) {
	146	hfs_btree_inc_height(tree);
	147	new_node->parent = tree->root;
	148	}
	149	fd->bnode = hfs_bnode_find(tree, new_node->parent);
	150
	151	/* create index data entry */
	152	cnid = cpu_to_be32(new_node->this);
	153	entry = &cnid;
	154	entry_len = sizeof(cnid);
	155
	156	/* get index key */
	157	hfs_bnode_read_key(new_node, fd->search_key, 14);
324ef39a	158	__hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key);
1da177e4 LT	159
	160	hfs_bnode_put(new_node);
	161	new_node = NULL;
	162
324ef39a VD	163	if ((tree->attributes & HFS_TREE_VARIDXKEYS) \|\|
324ef39a VD	164	(tree->cnid == HFSPLUS_ATTR_CNID))
1da177e4 LT	165	key_len = be16_to_cpu(fd->search_key->key_len) + 2;
1da177e4 LT	166	else {
2753cc28 AS	167	fd->search_key->key_len =
2753cc28 AS	168	cpu_to_be16(tree->max_key_len);
1da177e4 LT	169	key_len = tree->max_key_len + 2;
	170	}
	171	goto again;
	172	}
	173
1da177e4 LT	174	return 0;
	175	}
	176
	177	int hfs_brec_remove(struct hfs_find_data *fd)
	178	{
	179	struct hfs_btree *tree;
	180	struct hfs_bnode node, parent;
	181	int end_off, rec_off, data_off, size;
	182
	183	tree = fd->tree;
	184	node = fd->bnode;
	185	again:
	186	rec_off = tree->node_size - (fd->record + 2) * 2;
	187	end_off = tree->node_size - (node->num_recs + 1) * 2;
	188
	189	if (node->type == HFS_NODE_LEAF) {
	190	tree->leaf_count--;
	191	mark_inode_dirty(tree->inode);
	192	}
	193	hfs_bnode_dump(node);
c2b3e1f7	194	hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n",
2753cc28	195	fd->record, fd->keylength + fd->entrylength);
1da177e4 LT	196	if (!--node->num_recs) {
	197	hfs_bnode_unlink(node);
	198	if (!node->parent)
	199	return 0;
	200	parent = hfs_bnode_find(tree, node->parent);
	201	if (IS_ERR(parent))
	202	return PTR_ERR(parent);
	203	hfs_bnode_put(node);
	204	node = fd->bnode = parent;
	205
324ef39a	206	__hfs_brec_find(node, fd, hfs_find_rec_by_key);
1da177e4 LT	207	goto again;
1da177e4 LT	208	}
2753cc28 AS	209	hfs_bnode_write_u16(node,
	210	offsetof(struct hfs_bnode_desc, num_recs),
	211	node->num_recs);
1da177e4 LT	212
	213	if (rec_off == end_off)
	214	goto skip;
	215	size = fd->keylength + fd->entrylength;
	216
	217	do {
	218	data_off = hfs_bnode_read_u16(node, rec_off);
	219	hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
	220	rec_off -= 2;
	221	} while (rec_off >= end_off);
	222
	223	/* fill hole */
	224	hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
	225	data_off - fd->keyoffset - size);
	226	skip:
	227	hfs_bnode_dump(node);
	228	if (!fd->record)
	229	hfs_brec_update_parent(fd);
	230	return 0;
	231	}
	232
	233	static struct hfs_bnode hfs_bnode_split(struct hfs_find_data fd)
	234	{
	235	struct hfs_btree *tree;
b6b41424	236	struct hfs_bnode node, new_node, *next_node;
1da177e4 LT	237	struct hfs_bnode_desc node_desc;
	238	int num_recs, new_rec_off, new_off, old_rec_off;
	239	int data_start, data_end, size;
	240
	241	tree = fd->tree;
	242	node = fd->bnode;
	243	new_node = hfs_bmap_alloc(tree);
	244	if (IS_ERR(new_node))
	245	return new_node;
	246	hfs_bnode_get(node);
c2b3e1f7	247	hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n",
1da177e4 LT	248	node->this, new_node->this, node->next);
	249	new_node->next = node->next;
	250	new_node->prev = node->this;
	251	new_node->parent = node->parent;
	252	new_node->type = node->type;
	253	new_node->height = node->height;
	254
b6b41424 AV	255	if (node->next)
	256	next_node = hfs_bnode_find(tree, node->next);
	257	else
	258	next_node = NULL;
	259
	260	if (IS_ERR(next_node)) {
	261	hfs_bnode_put(node);
	262	hfs_bnode_put(new_node);
	263	return next_node;
	264	}
	265
1da177e4 LT	266	size = tree->node_size / 2 - node->num_recs * 2 - 14;
	267	old_rec_off = tree->node_size - 4;
	268	num_recs = 1;
	269	for (;;) {
	270	data_start = hfs_bnode_read_u16(node, old_rec_off);
	271	if (data_start > size)
	272	break;
	273	old_rec_off -= 2;
	274	if (++num_recs < node->num_recs)
	275	continue;
	276	/* panic? */
	277	hfs_bnode_put(node);
	278	hfs_bnode_put(new_node);
b6b41424 AV	279	if (next_node)
b6b41424 AV	280	hfs_bnode_put(next_node);
1da177e4 LT	281	return ERR_PTR(-ENOSPC);
	282	}
	283
	284	if (fd->record + 1 < num_recs) {
	285	/* new record is in the lower half,
	286	* so leave some more space there
	287	*/
	288	old_rec_off += 2;
	289	num_recs--;
	290	data_start = hfs_bnode_read_u16(node, old_rec_off);
	291	} else {
	292	hfs_bnode_put(node);
	293	hfs_bnode_get(new_node);
	294	fd->bnode = new_node;
	295	fd->record -= num_recs;
	296	fd->keyoffset -= data_start - 14;
	297	fd->entryoffset -= data_start - 14;
	298	}
	299	new_node->num_recs = node->num_recs - num_recs;
	300	node->num_recs = num_recs;
	301
	302	new_rec_off = tree->node_size - 2;
	303	new_off = 14;
	304	size = data_start - new_off;
	305	num_recs = new_node->num_recs;
	306	data_end = data_start;
	307	while (num_recs) {
	308	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	309	old_rec_off -= 2;
	310	new_rec_off -= 2;
	311	data_end = hfs_bnode_read_u16(node, old_rec_off);
	312	new_off = data_end - size;
	313	num_recs--;
	314	}
	315	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
	316	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
	317
	318	/* update new bnode header */
	319	node_desc.next = cpu_to_be32(new_node->next);
	320	node_desc.prev = cpu_to_be32(new_node->prev);
	321	node_desc.type = new_node->type;
	322	node_desc.height = new_node->height;
	323	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	324	node_desc.reserved = 0;
	325	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
	326
	327	/* update previous bnode header */
	328	node->next = new_node->this;
	329	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
	330	node_desc.next = cpu_to_be32(node->next);
	331	node_desc.num_recs = cpu_to_be16(node->num_recs);
	332	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
	333
	334	/* update next bnode header */
b6b41424	335	if (next_node) {
1da177e4 LT	336	next_node->prev = new_node->this;
	337	hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
	338	node_desc.prev = cpu_to_be32(next_node->prev);
	339	hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
	340	hfs_bnode_put(next_node);
	341	} else if (node->this == tree->leaf_tail) {
	342	/* if there is no next node, this might be the new tail */
	343	tree->leaf_tail = new_node->this;
	344	mark_inode_dirty(tree->inode);
	345	}
	346
	347	hfs_bnode_dump(node);
	348	hfs_bnode_dump(new_node);
	349	hfs_bnode_put(node);
	350
	351	return new_node;
	352	}
	353
	354	static int hfs_brec_update_parent(struct hfs_find_data *fd)
	355	{
	356	struct hfs_btree *tree;
	357	struct hfs_bnode node, new_node, *parent;
	358	int newkeylen, diff;
	359	int rec, rec_off, end_rec_off;
	360	int start_off, end_off;
	361
	362	tree = fd->tree;
	363	node = fd->bnode;
	364	new_node = NULL;
	365	if (!node->parent)
	366	return 0;
	367
	368	again:
	369	parent = hfs_bnode_find(tree, node->parent);
	370	if (IS_ERR(parent))
	371	return PTR_ERR(parent);
324ef39a	372	__hfs_brec_find(parent, fd, hfs_find_rec_by_key);
98cf21c6 SA	373	if (fd->record < 0)
98cf21c6 SA	374	return -ENOENT;
1da177e4 LT	375	hfs_bnode_dump(parent);
	376	rec = fd->record;
	377
	378	/* size difference between old and new key */
324ef39a VD	379	if ((tree->attributes & HFS_TREE_VARIDXKEYS) \|\|
324ef39a VD	380	(tree->cnid == HFSPLUS_ATTR_CNID))
1da177e4 LT	381	newkeylen = hfs_bnode_read_u16(node, 14) + 2;
	382	else
	383	fd->keylength = newkeylen = tree->max_key_len + 2;
c2b3e1f7	384	hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n",
2753cc28	385	rec, fd->keylength, newkeylen);
1da177e4 LT	386
	387	rec_off = tree->node_size - (rec + 2) * 2;
	388	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
	389	diff = newkeylen - fd->keylength;
	390	if (!diff)
	391	goto skip;
	392	if (diff > 0) {
	393	end_off = hfs_bnode_read_u16(parent, end_rec_off);
	394	if (end_rec_off - end_off < diff) {
	395
c2b3e1f7	396	hfs_dbg(BNODE_MOD, "splitting index node\n");
1da177e4 LT	397	fd->bnode = parent;
	398	new_node = hfs_bnode_split(fd);
	399	if (IS_ERR(new_node))
	400	return PTR_ERR(new_node);
	401	parent = fd->bnode;
	402	rec = fd->record;
	403	rec_off = tree->node_size - (rec + 2) * 2;
2753cc28 AS	404	end_rec_off = tree->node_size -
2753cc28 AS	405	(parent->num_recs + 1) * 2;
1da177e4 LT	406	}
	407	}
	408
	409	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
	410	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
	411	start_off -= 4; /* move previous cnid too */
	412
	413	while (rec_off > end_rec_off) {
	414	rec_off -= 2;
	415	end_off = hfs_bnode_read_u16(parent, rec_off);
	416	hfs_bnode_write_u16(parent, rec_off, end_off + diff);
	417	}
	418	hfs_bnode_move(parent, start_off + diff, start_off,
	419	end_off - start_off);
	420	skip:
	421	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
	422	hfs_bnode_dump(parent);
	423
	424	hfs_bnode_put(node);
	425	node = parent;
	426
	427	if (new_node) {
	428	__be32 cnid;
	429
	430	fd->bnode = hfs_bnode_find(tree, new_node->parent);
	431	/* create index key and entry */
	432	hfs_bnode_read_key(new_node, fd->search_key, 14);
	433	cnid = cpu_to_be32(new_node->this);
	434
324ef39a	435	__hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key);
1da177e4 LT	436	hfs_brec_insert(fd, &cnid, sizeof(cnid));
	437	hfs_bnode_put(fd->bnode);
	438	hfs_bnode_put(new_node);
	439
	440	if (!rec) {
	441	if (new_node == node)
	442	goto out;
	443	/* restore search_key */
	444	hfs_bnode_read_key(node, fd->search_key, 14);
	445	}
	446	}
	447
	448	if (!rec && node->parent)
	449	goto again;
	450	out:
	451	fd->bnode = node;
	452	return 0;
	453	}
	454
	455	static int hfs_btree_inc_height(struct hfs_btree *tree)
	456	{
	457	struct hfs_bnode node, new_node;
	458	struct hfs_bnode_desc node_desc;
	459	int key_size, rec;
	460	__be32 cnid;
	461
	462	node = NULL;
	463	if (tree->root) {
	464	node = hfs_bnode_find(tree, tree->root);
	465	if (IS_ERR(node))
	466	return PTR_ERR(node);
	467	}
	468	new_node = hfs_bmap_alloc(tree);
	469	if (IS_ERR(new_node)) {
	470	hfs_bnode_put(node);
	471	return PTR_ERR(new_node);
	472	}
	473
	474	tree->root = new_node->this;
	475	if (!tree->depth) {
	476	tree->leaf_head = tree->leaf_tail = new_node->this;
	477	new_node->type = HFS_NODE_LEAF;
	478	new_node->num_recs = 0;
	479	} else {
	480	new_node->type = HFS_NODE_INDEX;
	481	new_node->num_recs = 1;
	482	}
	483	new_node->parent = 0;
	484	new_node->next = 0;
	485	new_node->prev = 0;
	486	new_node->height = ++tree->depth;
	487
	488	node_desc.next = cpu_to_be32(new_node->next);
	489	node_desc.prev = cpu_to_be32(new_node->prev);
	490	node_desc.type = new_node->type;
	491	node_desc.height = new_node->height;
	492	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
	493	node_desc.reserved = 0;
	494	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
	495
	496	rec = tree->node_size - 2;
	497	hfs_bnode_write_u16(new_node, rec, 14);
	498
	499	if (node) {
500	/* insert old root idx into new root */
501	node->parent = tree->root;
502	if (node->type == HFS_NODE_LEAF \|\|
324ef39a VD	503	tree->attributes & HFS_TREE_VARIDXKEYS \|\|
324ef39a VD	504	tree->cnid == HFSPLUS_ATTR_CNID)
1da177e4 LT	505	key_size = hfs_bnode_read_u16(node, 14) + 2;
	506	else
	507	key_size = tree->max_key_len + 2;
	508	hfs_bnode_copy(new_node, 14, node, 14, key_size);
	509
324ef39a VD	510	if (!(tree->attributes & HFS_TREE_VARIDXKEYS) &&
324ef39a VD	511	(tree->cnid != HFSPLUS_ATTR_CNID)) {
1da177e4 LT	512	key_size = tree->max_key_len + 2;
	513	hfs_bnode_write_u16(new_node, 14, tree->max_key_len);
	514	}
	515	cnid = cpu_to_be32(node->this);
	516	hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
	517
	518	rec -= 2;
	519	hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
	520
	521	hfs_bnode_put(node);
	522	}
	523	hfs_bnode_put(new_node);
	524	mark_inode_dirty(tree->inode);
	525
	526	return 0;
	527	}